Stabilized knuckle joint



Nov. 10, 1964 T. M. FRISBY STABILIZED KNUCKLE JOINT 2 Sheets-Sheet 1 Filed Dec. 7, 1959 INVENTOR. THOMAS M. FRISBY ATT 2 Sheets-Sheet 2 T. M. FRISBY INVENTOR. THOMAS M. FRISBY AT ORNEY STABILIZED KNUCKLE JOINT Nov. 10, 1964 Filed Dec. 7, 1959 United States Patent 3,156,310 STABILIZED KNUCKLE JOINT Thomas M. Frisby, Denver, Colo., assiguor to Eastman Oil Well Survey Company, Denver, Colo., a corporation of Delaware Filed Dec. 7, 1959, Ser. No. 857,763 13 Claims. (Cl. 175-46) It is customary in the earth boring art to employ a radially displaceable joint, commonly referred to as a knuckle joint, together with means such as a wedge in closely spaced relation to the joint whereupon application of weight to the drill bit and by causing the wedge to bear against the side of the well bore, the bit may be caused to pivot about the joint in the desired direction for directional drilling.

In accordance with the present invention, it is proposed to obviate many of the drawbacks and disadvantages attending the use of known deflecting tools, such as limited degree of deflection, development of undue friction between the relative moving parts during the directional drilling operation and also the tendency of the tool and associated drill pipe section to oscillate unduly and wobble once positioned for drilling in the deflected position. Also, in addition to overcoming the above disadvantages and many others, the tool of the present invention is greatly simplified, eliminates a number of separate steps heretofore believed to be necessary in the use of many types of deflecting tools such as whipstocks and is extremely reliable in operation.

Accordingly, it is a principal object of the present invention to provide for deflecting tool which permits positive and reliable deflection of the drill bit, holds the drill bit in predetermined deflected relation for completely stabilized directional drilling in a well bore, and in doing so greatly minimizes wobbling and oscillation of the bit.

It is another object to provide a deflecting tool conformable for use with various types and sizes of drill bits and which is so constructed and arranged as to establish and maintain the deflection of a drill bit at a predetermined angle and in a predetermined direction for carrying out completely stabilized directional drilling in a Well bore.

It is a further object of the present invention to provide for a deflecting tool, of the type incorporating a radially displaceable joint therein, which is so constructed and arranged as to maintain the joint in off center relation for radial displacement in a predetermined direction to cause deflection of a drill bit in the opposite direction, and thereafter to provide for rotation of the drill pipe and drill bit in the predetermined direction while supporting the lower end of the drill pipe in completely stabilized relation.

It is a still further object to provide a deflecting tool for use in directional drilling operations which is capable of minimizing friction and wear of the relatively moving parts comprising the drill string and deflecting tool, is capable of accomplishing deflection of thetool over a wide angle of deflection with minimum oscillation of the tool during directional drilling so as to maintain the bit in the desired direction at all times, and further permits one-step drilling of a full gauge hole in the desired direction.

The above and other objects and advantages of the present invention will become more apparent from the 3,156,310 Patented Nov. 10, 19564 following detailed description taken together with accompanying drawings, in which:

FIGURE 1 is an elevational view of the lower end of a drill pipe in a well bore and illustrating a preferred form of deflecting tool, in accordance with the present invention;

- FIGURE 2 is a vertical section view of the deflecting tool in connected relation with the lower end of the drill FIGURE 2a is still another view, partially in section, of the lower extremity of the drill pipe together with the lower end portion of the deflecting tool, in accordance with the present invention and representing a continuation of the view shown in FIGURE 2;

FIGURE 3 is a view taken on line 33 of FIGURE 2a; and

FIGURE 4 is a view taken on line 4-4 of FIGURE 20:.

Referring more particularly to the drawings, there is shown by way of illustrative example a drill stem or drill pipe 16 adapted to be lowered into a well bore W and wherein the drill pipe has connected at the lower extremity thereof a drill bit 12 for rotation with the drill pipe to accomplish drilling of the well bore. For the purpose of describing the present invention, the drill pipe 1d may be identified as having an upper section 13 and lower section 14 and wherein the upper section 13 is provided with a stabilizer S which in accordance with well known practice is positioned on the drill pipe to properly center it within the well bore throughout the drilling operation. In addition, the lower section 14 of the drill pipe may be comprised of a stabilizer section 22 together with an inner mandrel 16 having a sub 17 threaded onto the lower end of the mandrel and in turn the drill bit 12 may be connected into the sub 17. An axially extending bore 18 also extends throughout the length of the drill pipe ill to form a central passage for the circulation of fluid therethrough and outwardly through the drill bit into the well bore in a well known manner.

In accordance with the present invention, the preferred form of deflecting tool is broadly comprised of a radially displaceable joint portion 20 preferably interposed between the upper and lower sections 13 and 14 respectively of the drill pipe together with the stabilizer section 22 carried on the lower section 14 between the joint 20 and drill bit 12 and a locking and release assembly 24 associated with the stabilizer section 22 and inner mandrel 16 which is effective to selectively engage and disengage the stabilizer means into and out of rotative engagement with the inner mandrel.

The joint 2% is essentially designed and disposed in association with the drill pipe 10 to accomplish radial displacement of the lower extremity of the drill string and drill bit in the desired direction and at the desired angle to deviate the angle of the well bore from the vertical the desired direction and extent, respectively. To best carry out the purposes of the present invention, the joint 20 is interposed between the inner mandrel forming a part of the lower section of the drill pipe and the upper section, although it will become apparent hereinafter that the joint may also be interposed between the drill bit and lower end of the mandrel but in such position will not be nearly as effective. Most desirably, the joint 20 of the present invention is of the type commonly referred to as a knuckle joint defined by a spherical head portion 26 tapering downwardly into a threaded extension 27 which is connected into a sub portion 28 projecting upwardly from the inner mandrel 16. The headportion 26 is adapted for positioning in a socket portion 30 connected at the lower extremity of the upper section 13 of the drill pipe, and the lower extremity itself may be suitably constituted of a sub 32 having an exteriorly threaded end portion 33. Forming a part of the socket for accommodating the enlarged head 26 is a collar 34 being interiorly threaded as at 35 for connection to the sub and with the inner wall of the collar curving inwardly to form a receptacle 36 for the head, then flaring outwardly to form a skirt 37.

In addition to the receptacle portion 36 of the collar 34 the top wall of the socket is defined by a generally concave seat portion 40 and if desired the seat portion may be disposed in the lower end of the sub 32 by forming a peripheral groove 41 at the upper end of the seat portion to mate with a downwardly extending annular flange portion 42 on the sub. In order to hold the enlarged head 26 in loosely fitting relation within the socket, the head is provided with a series of slots 44 spaced about the periphery thereof and each of the slots is generally circular and adapted to receive rounded lugs 45 projecting inwardly through the wall of the collar, the lugs act ing as pivotal members for radial displacement of the entire joint. In addition, the sides of the slot engage the ends of the lugs to impart rotation of the upper section of the drill pipe into the lower section while at the same time permitting the lugs to be freely pivotal in the slots so that the joint can deflect the lower section and drill bit relative to the upper section for directional drilling. Moreover, the lower end of the sub 32 includes an enlarged counterbore portion 48 in which is positioned a coiled compression spring 49, the spring being adapted to exert a constant downward force against the top surface of the seat portion 40 to urge it into firm contact with the head at all times and thus prevent circulation of drilling fluid around the head.

To initiate radial displacement of the universal joint and furthermore to stabilize the entire directional drilling operation, the stabilizer section 22 is carried by the lower section 14 of the drill pipe in such a way as to make the stabilizer section selectively rotatable with the drill pipe or non-rotatable independently of the drill pipe as desired. To this end the stabilizer section comprises an outer sleeve 50 which is most desirably of a length corresponding to that of the inner mandrel 16 and the sleeve is carried on the inner mandrel preferably by means of upper and lower bearings 52. Bearings 52 include rollers 53 disposed in races 54 which are mounted between the facing surfaces at the upper and lower ends of the sleeve 50 and inner mandrel 16 respectively. In addition, a thrust bearing 55 is disposed above the upper roller bearings 52 and includes balls 56 mounted in races 57 and to hold the races 57 in position over the top edge of the sleeve a thrust collar 58 is threaded onto the inner mandrel above the bearing 55. Through this relative disposition and arrangement of the sleeve and inner mandrel the roller bearings 54 are adapted to permit the inner mandrel 16 to rotate freely independently of the sleeve 50 notwithstanding the application of any lateral forces on the sleeve while the upper thrust bearing 55 permits free relative rotation notwithstanding application of vertical forces therebetween.

The stabilizer section 22 further includes ontwardly projecting ribs or stabilizer elements forming a ring-like stabilizer 60 adjacent one end of the sleeve and a stabilizer 61 adjacent the opposite end of the sleeve. By selectively dimensioning the stabilizer 60 to be of graduated thickness, it is possible to mount the entire stabilizer assembly and lower section 14 in off-center relation and to maintain the joint 20 in off-center relation so that the top of the tool will always knuckle or become angularly displaced away from the vertical when weight is applied through the entire drill pipe. Moreover, the stabilizer 61 is proportioned to cause vertical deflection in cooperation with the stabilizer 60 of the mandrel and sleeve in the desired direction. Preferably, the stabilizer 60 takes the form of a segmental ring wherein the segments are regulated in thickness on the sleeve such that the ring is generally eccentric or elliptical in cross section and generally corresponds in length along its major axis to the diameter of the well bore. More specifically, the stabilizer 60 may be defined by a central stabilizer element 60A as shown in FIGURE 3 which is relatively thin and may be pro vided with a series of vertical ridges 62 on the exterior surface thereof. From the element 60A, flanking stabilizer elements 60B are correspondingly increased in thickness in accordance with the greater radius from an eccentric center selected. On the opposite side of the sleeve the stabilizer elements 60C, which are evenly spaced about the major axis, are of increased thickness to conform to the radial distance from another eccentric center chosen so as to be gauged together with the elements 60A and 6013 close to the overall diameter of the drill bit 12. In turn stabilizer elements 61, as shown in FIGURE 4, are preferably spaced vertically below the elements 69B and slope downwardly and outwardly to provide a gradually increased depth or thickness so that the joint and drill pipe are displaced to vertically deflect the drill bit in the opposite direction against the side of the well bore. Actually, the thickness of the stabilizers 61 is governed in accordance with the relative thickness of the elements 60A and 6013 to deflect the drill bit in the desired direction and in this connection may form vertical continuations of elements 60B, and also of element 60A if desired rather than to be spaced below the elements. Through the above described disposition and arrangement of the eccentrically disposed stabilizer members it will be seen that as the drill pipe and associated deflecting tool is lowered through the well bore, the joint will be constantly maintained in off-center relation, as illustrated in FIGURE 1, and as the drill bit 12 is landed at the bottom of the well bore at the point of desired deflection and upon the application of weight thereto by the drill pipe the joint will be caused to move laterally or radially to an even greater extent in the same direction with the elements 60A, 60B and 61 bearing hard against the wall of the well bore. Of course the extent of deflection is established through regulation of the relative thickness of the ribs or stabilizer elements. Essentially, therefore, the stabilizers are designed to provide a vertical bearing portion on one side of the mandrel or drill pipe which is sloped at a gradually increased thickness in vertical relation, as defined by elements 60A, 60B and 61, to maintain the pipe in deflected relation and a peripheral stabilizer 60 dimensioned to be of increased thickness beginning at the point of least thickness on the bearing portion to maintain the joint and drill pipe in off-center relation.

As a preliminary to the directional drilling operation itself and subsequent to landing the drill bit at the bottom of the hole, it is necessary to properly establish the direction of deflection of the drill bit and this may be suitably carried out by any one of a number of orienting methods well known to the art, such as by use of an orienting tool, commonly referred to as a mule shoe and as shown and disclosed in the patent to Bremner et al., No. 2,207,505.

Again, it is emphasized that various types of locking and release assemblies may be employed, and the one employed in the deflecting tool of the present invention is preferably of the type responsive to changes or varia tions in fluid pressure in the axial bore 18 to cause selective locking and release of the sleeve relative to the mandrel. A suitable locking and release assembly which may be employed to this end is that described in the patent to James et al., No. 2,819,040, and wherein a slideable piston member 70 is positioned within the bore 18 extending through the mandrel 16 so as to define a bore 18' of less diameter than the outer bore 18. The piston 70 is normally biased upwardly against a shoulder 71 by means of a coil spring 73 positioned in an annular space 72 formed between the piston and lower shoulder 74 on the mandrel. Under normal fluid circulation the spring 73 is formed to be of suificient strength to overcome the downward force of the fluid and maintain the piston in upwardly biased relation, Positioned in a slot 76 on the exterior surface of the mandrel is a sliding block 77 adapted to ride upwardly and downwardly in the slot and similarly an inwardly projecting lug 78 is carried by the block for projection through an elongate slot 79 and which is threaded at its innermost end for connection in a threaded bore provided on the piston for that purpose. The block 77 is proportioned to move into a slot 80 which is formed on a shoulder 81 projecting downwardly and inwardly from the wall of the stabilizer sleeve 50. When the fluid pressure is therefore increased in the bores 18 and 18 a sufficient differential pressure will be established between the bore passages to cause a resultant downward force suflicient to overcome the upward bias of the spring and accordingly to force the piston, lug and block downwardly so that the block moves away from the slot.

When the deflecting tool and bit are being oriented, of course the piston will be in the upwardly biased position so that the sleeve will be locked for rotation with the mandrel by means of the slot 80 receiving the block 77. Upon completion of orientation and before the directional drilling operation is commenced, the increase of pressure caused by the circulation of fluid through the central passage formed by the bores will be sufiicient to force the piston downwardly against the bias of the spring and to release the sleeve from rotation with the mandrel during directional drilling.

Following orientation of the deflecting tool and upon release of the sleeve and stabilizer section 22, application of weight to the drill bit will of course cause radial displacement of the joint as described and due to the eccentric arrangement and spacing of the stabilizers the drill bit will be positively urged in the desired direction for directional drilling. Of course as the stabilizer ele ments 60 and 61 are caused to bear firmly against the wall of the well bore and due to the arrangement of bearings between the sleeve and mandrel, notwithstanding the lateral force imposed by the mandrel together with the Weight of the drill string acting against the sleeve, the bearing arrangement will effectively eliminate any tendency for the sleeve to rotate with the drill pipe and will substantially eliminate any frictional engagement therebetween. Also the stabilizer members together with the sleeve 50 are spaced and removed completely from any association with the drill bit and accordingly the drill bit may be sized to full gauge to permit the directional drilling operation to be carried out without employing a successive number of reaming operations to bring the deflected hole up to full size. Moreover, as the directional drilling operation progresses, it will be noted that the eccentric arrangement of the stabilizers will bring the lower section of the drill pipe into contiguous relation With the Wall of the well bore on all sides so that any tendency of the drill bit to oscillate due to its deflected relation with the upper section of the drill pipe will be absorbed by the stabilizers bearing against the Wall of the well bore so that the bit will be held in the desired direction at all times.

It will thus be apparent that there is provided a unique type of deflecting tool which incorporates all the advantages, for example, of a knuckle joint alone and a whipstock alone while eliminating many of the disadvantages heretofore associated with them. Moreover, the tool is adjustable and accurate in establishing desired aligmnent and deflection of the tool in the desired direction and maintains complete stability of the tool and prevents oscillation thereof as the directional drilling operations are being conducted. Moreover, any friction between the parts is minimized by the bearing and stabilizer construction and it is made possible to drill a full gauge hole while holding the drill bit securely in position against any wobbling or oscillation. Of course, it is to be understood that various changes in the size, shape and materials as well as the details of the illustrated construction may be made without departing from the scope of the present invention as defined by the appended claims.

What is claimed is:

1. In directional drilling apparatus including a knuckle joint between upper and lower pipe sections of a pipe string, the improvement which comprises stabilizer means including upper and lower sets of circumferentially spaced stabilizer elements on said lower pipe section of fixed lateral extent from said lower pipe section, the upper set comprising elements spaced entirely around the circumference of said pipe, the stabilizer elements of said lower set located immediately beneath elements of said upper set being of different lateral extent than said corresponding stabilizer elements of the upper set, whereby when said pipe section is in a bore hole said lower pipe section will be aligned at an angle by means of said joint and the cooperation of said stabilizing elements with the surface of said bore hole.

2. Directional drilling apparatus comprising: in combination, an upper stabilized pipe section; a lower pipe section; a knuckle joint connecting the lower end of said upper pipe section and the upper end of said lower pipe section constructed to permit lateral displacement of the lower end of said lower pipe section with respect to the vertical axis of said upper pipe section; a drill connected to the lower end of said lower pipe section; said upper pipe section, joint and lower pipe section forming a pipe string for transmitting rotary power to said drill and conducting fluid thereto under pressure; an outer sleeve rotatably mounted over said lower pipe section; locking means for locking said sleeve against rotation and unlocking it; stabilizer means including upper and lower sets of circumferentially spaced stabilizer elements on said lower pipe section of fixed lateral extent from said lower pipe section, the upper set comprising elements spaced entirel y around the circumference of said pipe, the stabilizer elements of said lower set located immediately beneath corresponding stabilizer elements of said upper set being of different lateral extent than said corresponding stabilizer elements of the upper set.

3. Claim 2 in which bearing means are provided between the sleeve and lower pipe section to permit relative rotation therebetween under the application of lateral and vertical forces to said lower pipe section.

4. Claim 3 in which bearings are provided between the internal surface of said sleeve and the external surface of said lower pipe section and between the upper edge of said sleeve and said lower pipe section.

5. A deflecting tool adapted for use in directionally drilling a well bore comprising a laterally displaceable joint interposed between adjacent upper and lower sections of a drill pipe in spaced relation above a drill bit positioned at the lower extremity of the drill pipe, said joint comprising a mutually cooperating ball and socket providing limited rotation of said ball in said socket to permit lateral displacement of the lower end of said lower pipe section with respect to the vertical axis of said upper pipe section, stabilizer means mounted on the drill pipe between said joint and the drill bit for disposition of said joint in normally off center relation in the well bore, said stabilizer means including a sleeve disposed in outer concentric relation on said drill pipe and a generally eccentric stabilizer means on said sleeve corresponding in cross-sectional size with the well bore comprising upper and lower extensions of fixed lateral extent from said sleeve, corresponding vertically aligned parts of said upper and lower extensions being of different lateral extent, and locking means between said sleeve and drill pipe engageable with said sleeve to lock said stabilizer means for rotation with the drill pipe, said locking means being movable by pressure of the drilling fluid away from said sleeve to release said stabilizer means for rotation of the drill pipe and drill bit independently of said stabilizer means once said joint and drill bit are positioned in desired off center relation in the well bore.

6. A deflecting tool adapted for use in directionally drilling a well bore comprising a radially displaceable knuckle joint interposed between adjacent sections of a fluid conducting drill pipe in spaced relation above a drill bit positioned at the lower extremity of the drill pipe, stabilizer means including a sleeve mounted in outer concentric relation on said drill pipe between said joint and said drill bit and having upper and lower sets of circumferentially spaced stabilizer elements of fixed lateral extent from said sleeve, the stabilizer elements of said lower set located immediately beneath corresponding stabilizer elements of said upper set being of different lateral extent than said corresponding stabilizer elements of the upper set.

7. A stabilized knuckle joint to cause the predetermined deflection of the lower end of a drill pipe for conducting fluid under pressure and attached drill bit comprising a radially displaceable joint interconnecting upper and lower sections of the drill pipe, stabilizer means includ ing a sleeve carried on the lower section of the drill pipe between said joint and the drill bit having upper and lower sets of circumferentially spaced stabilizer elements of fixed lateral extent from said sleeve, the stabilizer elements of said lower set located immediately beneath corresponding stabilizer elements of said upper set being of diflferent lateral extent than said corresponding stabilizer elements of the upper set and operative to dispose said radially displaceable joint in ofl center relation in the well bore, bearing members mounting said sleeve for rotation of the drill pipe independently of said sleeve, a locking member between said sleeve and drill pipe normally keying said sleeve for rotation with the drill pipe including resilient means normally urging said locking member into keyed relation, said locking member comprising a piston inside the bore of said lower section of the drill pipe connected to said locking member and being responsive to fluid pressure to unlock said locking member and cause relative movement of the drill pipe and locking member away from keyed relation with said sleeve for rotation of the drill pipe independently of said sleeve, said joint being displaceable under the weight of the drill pipe for radial movement in accordance with its original oft center disposition to cooperate with said stabilizer elements to cause deflection of said bit in an opposite direction and said stabilizer elements together corresponding in diameter with that of the well bore to bear against the wall of the well bore in such a way as to hold said drill bit in predetermined deflected relation.

8. A stabilized knuckle joint according to claim 7, said radially displaceable joint being defined by interconnected head and socket portions, said socket portion having inwardly projecting pivotal members and said head portion being slotted to receive said pivotal members.

9. A stabilized knuckle joint according to claim 7, said stabilizer means being further characterized by a generally eccentric ring of fixed lateral extent from said sleeve and being graduated in said lateral extent and a vertical bearing portion in vertical spaced relation to said eccentric ring on said sleeve of fixed lateral extent from said sleeve and of different lateral extent from said eccentric ring and being cooperative therewith to cause angular deflection of said drill bit in a predetermined direction.

10. A stabilized knuckle joint according to claim 9, said vertical bearing portion being disposed in vertical spaced relation to the portion of least thickness on said eccentric ring.

11. In a deflecting tool adapted for use in directionally drilling a well bore, the combination of a pivotal joint interposed between adjacent sections of a drill pipe for conducting fluid under pressure, said pivotal joint being disposed in spaced relation above a drill bit positioned at the lower extremity of the drill pipe, and stabilizer means including a sleeve disposed in outer concentric relation to said drill pipe between said pivotal joint and the drill bit, a first generally eccentric stabilizer element comprising at least two ribs on said sleeve of fixed lateral extent from said sleeve and in directly opposed positions and a second stabilizer element comprising at least one lower rib on said sleeve of fixed lateral extent from said sleeve and being disposed in vertical spaced relation to said first stabilizer element with said lower rib directly beneath one of said two ribs, said lower rib being of different lateral extent than said upper ribs thereby to cooperate with said first stabilizer element and said pivotal joint to cause angular deflection of the drill pipe in a predetermined direction in the well bore.

12. In a deflecting tool according to claim 11 wherein said first stabilizer element is defined by an eccentric ring being graduated in thickness and of a diameter slightly less than that of the well bore.

13. In a deflecting tool according to claim 11 wherein said pivotal joint is defined by interconnected head and socket portions, said socket portion including inwardly projecting pivotal members and said head portion being slotted to receive said pivotal members thereby to impart rotation between adjacent sections of the drill pipe while being pivotal in a lateral direction to provide for deflection of the drill bit.

References Cited in the file of this patent UNITED STATES PATENTS 2,173,309 Monroe Sept. 19, 1939 2,712,434 Giles et al July 5, 1955 2,730,328 Brown Jan. 10, 1956 2,745,635 Zublin May 15, 1956 2,819,040 James et al Jan. 7, 1958 2,829,864 Knap Apr. 8, 1958 2,891,769 Page et al. June 23, 1959 2,919,897 Sims Jan. 5, 1960 

1. IN DIRECTIONAL DRILLING APPARATUS INCLUDING A KNUCKLE JOINT BETWEEN UPPER AND LOWER PIPE SECTIONS OF A PIPE STRING, THE IMPROVEMENT WHICH COMPRISES STABILIZER MEANS INCLUDING UPPER AND LOWER SETS OF CIRCUMFERENTIALLY SPACED STABILIZER ELEMENTS ON SAID LOWER PIPE SECTION OF FIXED LATERAL EXTENT FROM SAID LOWER PIPE SECTION, THE UPPER SET COMPRISING ELEMENTS SPACED ENTIRELY AROUND THE CIRCUMFERENCE OF SAID PIPE, THE STABILIZER ELEMENTS OF SAID LOWER SET LOCATED IMMEDIATELY BENEATH ELEMENTS OF SAID UPPER SET BEING OF DIFFERENT LATERAL EXTENT THAN SAID CORRESPONDING STABILIZER ELEMENTS OF THE UPPER SET, WHEREBY WHEN SAID PIPE SECTION IS IN A BORE HOLE SAID LOWER PIPE SECTION WILL BE ALIGNED AT AN ANGLE BY MEANS OF SAID JOINT AND THE COOPERATION OF SAID STABILIZING ELEMENTS WITH THE SURFACE OF SAID BORE HOLE. 